The National Party's decision to vote against a marine mammals bill shows a lack of commitment to conservation, says the Green Party.
The Marine Animals Protection Law Reform Bill was voted down by National and ACT on its first reading in Parliament on Wednesday night.
The members bill, which was sponsored by Greens' co-leader Metiria Turei, sought to provide greater protection to marine mammals.
Ms Turei says National has broken an election promise to ensure the recovery of the hectors and maui dolphin populations.
National says it respects the bill's intentions, but would prefer to work with industry rather than resort to legislation.